> And I was fairly certain I hadn't enabled the "FAIL_MAIL_OVER_500_MILES" option.
If this actually was a config option, I would bet anything the default would inexplicably be set to "true".
If this actually was a config option, I would bet anything the default would inexplicably be set to "true".
Because, at least on my system, looking at iwlwifi...
parm: 11n_disable:disable 11n functionality, bitmap: 1: full, 2: disable agg TX, 4: disable agg RX, 8 enable agg TX (uint)
So 8 is only aggregated TX, while 1 would be aggregated TX and RX. (It does, however, also inexplicably default to 0 on my system.)
e: Oh, apparently this is a pathological re-use of an existing module flag to force something on that they disabled due to instability in some cases, see also:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/lin...
So I'm sorry, but my assumption about =1 is not valid, as I assumed that all of the bits (1,2,4,8) were mutating the same thing, not "one bit does something VERY DIFFERENT".
A quick google turns up lots of people agreeing with you, suggesting the intel wireless driver seems to have trouble on 802.11n. Fine. But 8?
modinfo iwlwifi
parm: 11n_disable:disable 11n functionality, bitmap: 1: full, 2: disable agg TX, 4: disable agg RX, 8 enable agg TX (uint)
Side note: 11n_disable=8 as a way to enable an advanced wifi settings is not the most user-friendly option in the world. It looks like this was added as a patch to fix a compatibility issue with certain NICs[1]. Be careful setting it higher than 8 -- as that would set other flags in the bitmask, potentially turning off 802.11n entirely!
I've not heard of AMPDU before -- but it seems to be an 802.11n-specific protocol extension that allows you to send multiple MPDU blocks (i.e. frames) to the router at a time, rather than one at a time. This seems to trade off latency for error correction between a client and the router [2][3]. So by setting this flag, you're able to transmit multiple frames at a time, rather than retrying each frame individually until it goes through on a busy channel. This really does seem to make a difference, one report online suggests tx throughput goes from 20Mbit/s to 80Mbit/s when agg TX is enabled[4].
Apparently this was introduced in 2014 in order to patch a firmware issue on certain intel NICs. There's a whole conversation on the linux-wireless list about it[5], which seems to conclude that they couldn't reproduce the issue[6]:
> I have seen reports from many users and many devices - and unfortunately I have never been able to reproduce - so I can't know if it affects all the devices. All I can see is that I saw reports on very old devices (5150) and with more recent devices (2230).
[1]: https://github.com/torvalds/linux/commit/205e2210daa975d92ac... [2]: https://routerguide.net/optimize-ampdu-aggregation-on-or-off... [3]: http://eprints.eemcs.utwente.nl/21008/01/eunice.pdf [4]: https://ubuntuforums.org/printthread.php?t=2205924&pp=75 [5]: https://www.spinics.net/lists/linux-wireless/msg118549.html [6]: https://www.spinics.net/lists/linux-wireless/msg118554.html
The importance of full stops outside the quotes ;-)
I happen to disagree with them, but they have been considered authorities on the proper way to write in the English language for many decades.
British style, on the other hand, specifies that a period goes outside the quotations.
http://blog.apastyle.org/apastyle/2011/08/punctuating-around...